1. Field of the Invention
The present invention relates to automatic warewashers for kitchenware; and in particular to electronic control circuits for automatically operating the warewasher.
2. Description of the Related Art
Commercial kitchens have equipment to clean and sanitize glassware, dishes, silverware, pot, pans and cooking utensils, which are collectively referred to as “kitchenware.” Such equipment, commonly known as a “dishwasher” or more generically as a “warewasher”, has a cabinet defining an internal chamber into which trays of kitchenware are placed for washing. A washing and rinsing assembly within the chamber has a plurality of nozzles from which water sprays onto the kitchenware being cleansed. The lower part of the cabinet forms a reservoir that collects the water which is repeatedly circulated through the nozzles by a pump during the wash cycle. Then, fresh water from an external supply line is fed through the nozzles during a rinse cycle. When the rinse water flows into the reservoir, some of the reservoir water overflows into a drain thus replacing some of the water from the wash cycle.
Because the water is not completely drained from the reservoir for each wash cycle, food particles, grease and other debris from the kitchenware accumulates in the reservoir. As a result a human operator periodically (e.g. every two hours of operation) must manually drain and refill the warewasher to remove the accumulated debris and provide fresh water. Operators often forget to change the water or lose track of how long the time interval has been since the previous water change.
To solve this problem, various systems have been developed to remind the operator when to change the water. One such system, counted the number of wash cycles and upon the occurrence of a given number of cycles, provided a visual or audible warning to the operator indicating the need to change the wash water. For example, a lamp on a control panel illuminated and a buzzer sounded to provide that indication. However, operators often ignored this warning, pressed a reset switch and continued to wash dishes without changing the water in the warewasher. Failure to periodically drain and refill the machine with fresh water allows debris to accumulate to unsatisfactory levels which adversely affects proper cleaning of the kitchenware.
Therefore, there still exists a need for a control system that requires operators occasionally drain and refill the water in a warewashing machine.